Optimized osteogenesis of biological hydroxyapatite-based bone grafting materials by ion doping and osteoimmunomodulation.

BACKGROUND: Biological hydroxyapatite (BHA)-based bone grafting materials have been widely used for bone regeneration in implant surgery. Much effort has been made in the improvement of their osteogenic property as it remains unsatisfactory for clinical use. Osteoimmunomodulation plays a significant role in bone regeneration, which is highly related to active inorganic ions. Therefore, attempts have been made to obtain osteoimmunomodulatory BHA-based bone grafting materials with optimized osteogenic property by ion doping. OBJECTIVE: To summarize and discuss the active inorganic ions doped into BHA and their effects on BHA-based bone grafting materials. METHOD: A literature search was performed in databases including Google Scholar, Web of Science and PubMed, with the elementary keywords of "ion doped" and "biological hydroxyapatite", as well as several supplementary keywords. All document types were included in this search. The searching period and language were not limited and kept updated to 2022. RESULTS: A total of 32 articles were finally included, of which 32 discussed the physiochemical properties of BHA-based biomaterials, while 12 investigated their biological features in vitro, and only three examined their biological performance in vivo. Various ions were doped into BHA, including fluoride, zinc, magnesium and lithium. Such ions improved the biological performance of BHA-based biomaterials, which was attributed to their osteoimmunomodulatory effect. CONCLUSION: The doping of active inorganic ions is a reliable strategy to endow BHA-based biomaterials with osteoimmunomodulatory property and promote bone regeneration. Further studies are still in need to explore more ions and their effects in the crosstalk between the skeletal and immune systems.

Post-acute psychological effects of classical serotonergic psychedelics: a systematic review and meta-analysis.

BACKGROUND: Scientific interest in the therapeutic effects of classical psychedelics has increased in the past two decades. The psychological effects of these substances outside the period of acute intoxication have not been fully characterized. This study aimed to: (1) quantify the effects of psilocybin, ayahuasca, and lysergic acid diethylamide (LSD) on psychological outcomes in the post-acute period; (2) test moderators of these effects; and (3) evaluate adverse effects and risk of bias. METHODS: We conducted a systematic review and meta-analysis of experimental studies (single-group pre-post or randomized controlled trials) that involved administration of psilocybin, ayahuasca, or LSD to clinical or non-clinical samples and assessed psychological outcomes ⩾24 h post-administration. Effects were summarized by study design, timepoint, and outcome domain. RESULTS: A total of 34 studies (24 unique samples, n = 549, mean longest follow-up = 55.34 weeks) were included. Classical psychedelics showed significant within-group pre-post and between-group placebo-controlled effects on a range of outcomes including targeted symptoms within psychiatric samples, negative and positive affect-related measures, social outcomes, and existential/spiritual outcomes, with large between-group effect in these domains (Hedges' gs = 0.84 to 1.08). Moderator tests suggest some effects may be larger in clinical samples. Evidence of effects on big five personality traits and mindfulness was weak. There was no evidence of post-acute adverse effects. CONCLUSIONS: High risk of bias in several domains, heterogeneity across studies, and indications of publication bias for some models highlight the need for careful, large-scale, placebo-controlled randomized trials.

Clinical evaluation of ceramic implant abutments in anterior restorations.

The development of new high strength ceramic abutments can enhance the overall aesthetic outcome of an implant-supported prosthesis. This study was to compare the clinical application of alumina and zirconia ceramic implant abutments in the anterior region. Twenty-three consecutive patients requiring single-tooth implants in the anterior region were randomized to receive either an alumina ceramic abutment (CeraAdapt) or a zirconia ceramic abutment. All-ceramic (IPS-Empress 2) crowns were then fabricated and cemented over the abutments with composite cement. Peri-implant mucosal health and bone levels were evaluated by the gingival index and radiographs at 2-week and 1-year follow-up. Aesthetic outcomes as well as technical problems with the restorations were evaluated during the observation period from 12 to 48 months after functional loading. A total of 17 alumina ceramic abutments and 18 zirconia ceramic abutments were evaluated. No patients dropped out during the study period. Eighteen out of the 23 patients maintained good function throughout the study. The median observation period was 21 months. Ceramic crown loosening was found in two restorations at 1-week and 2-years respectively after insertion. One ceramic crown fractured at 1 week after insertion. At 1-year follow-up, mean marginal bone loss around implants was 1.2 +/- 0.5 mm and the peri-implant mucosa in relation to abutment or crown was healthy with a mean gingival score of 0.6 +/- 0.2. All patients were satisfied with the final aesthetic outcome. However, two alumina abutments fractured after two years of loading. In conclusion, both ceramic abutments have shown a favourable biological response and aesthetic outcome; however, zirconia abutments with their superior mechanical properties might be better for supporting single-tooth implant restorations in the aesthetic zone.